A device for testing fracture toughness of brazed joints

Abstract

A device for testing fracture toughness of brazed joints belongs to the technical field of mechanical performance testing. It includes a support seat (7), a loading device and a data acquisition system. A circular boss (72) is provided on the upper side of the support seat (7). The axis of the circular boss (72) is set horizontally. The sample (1) passes through the The arc-shaped groove (11) is rotatably set on the circular boss (72), the loading device includes a wedge-shaped indenter (2), and a measuring sample (1) is connected between the two base materials (13). The displacement measuring mechanism of the displacement, the loading device is connected with a load sensor (4), and both the load sensor (4) and the displacement measuring mechanism are connected to the data acquisition system. The wedge-shaped indenter is always loaded perpendicular to the sample, which ensures that the loading line is parallel to the brazing seam and improves the reliability of the load data. The device is stable and reliable, and it is easy to form a unified test standard for fracture toughness of brazed joints.

Description

technical field [0001] A brazing joint fracture toughness testing device belongs to the technical field of mechanical property testing. Background technique [0002] Plate-fin heat exchangers are widely used in petrochemical, aerospace, nuclear power and other industries because of their compact structure and high heat exchange efficiency. The fins and partitions of plate-fin heat exchangers are generally connected by vacuum brazing process, so there are a large number of brazed joints in the plate-fin structure. The brazed joints are the weakest part of the plate-fin structure, and the failure of the plate-fin structure Cracks often start at the edge of the brazing joint, and defects such as micro-cracks and voids at the brazing joint are the main inducing factors for the failure of the brazed joint. In the brazed joint structure, once various defects occur, the brazed joint will crack and expand until the component breaks. Therefore, it is particularly important to accur...

AI Technical Summary

Problems solved by technology

The existing commonly used fracture toughness standards include compact tensile specimens, three-point bending specimens, C-shaped tensile specimens and circular compact tensile specimens. These specimen standards are mainly applied to homogeneous materials. Fracture toughness testing of brazed joints is for further study

The three-point bending sample is simple and easy to process, but its installation accuracy is difficult to achieve, and the loading line is difficult to guarantee

At present, there is no test standard for the fracture toughness test of brazed joints in China. The existing test equipment for fracture toughness of homogeneous materials is complex, poor in stability, low in test accuracy, and difficult to form a unified test standard. Fracture toughness testing device for welded joints

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